1. Field of the Invention
The present invention relates to a liquid crystal display device including a transistor using an oxide semiconductor and a touch panel including the liquid crystal display device.
2. Description of the Related Art
Transistors which are used for many liquid crystal display devices and organic EL display devices have been formed using a silicon semiconductor film such as an amorphous silicon film or a polycrystalline silicon film.
Instead of the silicon semiconductor film, a technique in which an oxide semiconductor film is used for transistors has attracted attention.
For example, a technique is disclosed in which a transistor manufactured using an In—Ga—Zn oxide film as an oxide semiconductor is used as a switching element or the like of a pixel (see Patent Documents 1 and 2).
Further, we develop a technique in which an oxide semiconductor film having a noble crystal structure is manufactured over a glass substrate (see Non-Patent Document 1).